The European Southern Observatory (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy to enable important scientific discoveries and is the most productive ground-based observatory in the world. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in northern Chile, giving astronomers access to some of the clearest skies in the southern hemisphere: La Silla, Paranal and Chajnantor (ALMA and APEX). And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope which will become “the world's biggest eye on the sky”. At our exhibition stand (Booth 341), learn more about ESO's instruments and facilities and how it has brought Europe to the forefront of ground-based astronomy.